Air Cleaning Apparatus

ABSTRACT

Air to be cleaned by the apparatus is passed continuously through a unitary housing enclosing a partial-cyclone device, a rotating drum filter, and other filtering means arranged in sequence for progressively removing matter from the air. The apparatus may be economically fabricated and installed, and is so designed and constructed as to efficiently clean large volumes of air with minimum pressure losses.

United States Patent [191 Baigas, Jr.

[ 1 Feb. 4, 1975 AIR CLEANING APPARATUS [76] Inventor: Joseph F. Baigas,Jr., 4901 Sentimen Post Rd., Charlotte, NC. 28203 22 Filed: Dec. 20,1972 21 Appl. No.:316,758

[52] US. Cl 55/290, 55/294, 55/320,

55/337, 55/418, 55/430, 55/459, 55/482 [51] Int. Cl B01d 50/00 [58]Field of Search 55/290, 294, 318, 320,

[56] References Cited UNITED STATES PATENTS 453,143 5/1891 Eaton 55/392477,692 6/1892 McConnell 251/298 X 969,074 8/1910 Morse 55/290 1,759,3825/1930 Whitmore 55/394 X 2,170,704 8/1939 Bourne 55/392 2,316,836 4/1943Brever 55/337 3,053,700 9/1962 Kulp 15/312 A X 3,188,680 6/1965 Black15/312 A 3,409,131 11/1968 Petersen et al. 55/339 X 3,667,195 6/1972Angilly et a1. 55/290 X 3,695,012 10/1972 Rolland 55/521 X PrimaryExaminer-Bernard Nozick Attorney, Agent, or Firm-Joseph H. Heard [57]ABSTRACT Air to be cleaned by the apparatus is passed continuouslythrough a unitary housing enclosing a partialcyclone device, a rotatingdrum filter, and other filtering means arranged in sequence forprogressively removing matter from the air. The apparatus may beeconomically fabricated and installed, and is so designed andconstructed as to efficiently clean large volumes of air with minimumpressure losses.

7 Claims, 4 Drawing Figures PATENTEI] FEB 41975 SHEET 1 BF 2 PATENTEU41975 SHEET 2 [1F 2 1 AIR CLEANING APPARATUS BACKGROUND OF THE INVENTIONvicinity of the fiber-processing operation. The suction devices may beassociated with entire processing operations or areas, or withindividual fiber-processing machines therein. In the case of the cardingoperation, for example, various fly-generating sections of theindividual cards of a series of carding machines may be enclosed byhoods or shrouds, through which air is continuously withdrawn while themachines are in operation. Such a system may illustratively encompass100 carding machines each requiring 1,000 CFM of air at a negativepressure, at the card suction orifice, equivalent to 4 inches of water.

A system of the type described above must of course include some meansfor subsequently removing, from the air employed in the system, theparticulate matter entrained therein. Such removal should beaccomplished with maximum efficiency and minimum pressure-head losses,since otherwise the cost of operating the system could easily becomeexcessive. Rotatingdrum filters, by themselves or sometimes inassociation with other filtering means, have heretofore been proposedfor the aforesaid purpose. However, when the air contains largequantities of entrained particulate matter, as is frequently the case,filters of the aforesaid type quickly become loaded in operation, evenwhen equipped with automatic stripping means, and as a result undergosevere drops in efficiency. In an effort to alleviate the aforesaidproblem, it has also been heretofore proposed to first remove part oftheparticlate matter from the air by passing the same through aconventional cyclone device disposed upstream from the rotating-drumfilter. This, however, presents additional problems. Conventionalcyclone devices are relatively expensive both from the viewpoint offabrication and the viewpoint of installation. Additionally, theconsiderable size of a conventional cyclone device does not permit itsuse at all in some installations, or at best requires that the device belocated some distance from the rotating-drum filter and the remainingcomponents of the system. In the latter case, the requisite additionalduet-work increases installation costs and also duct pressure losses. Afurther and perhaps most important disadvantage, which is presentirrespective of the foregoing considerations, resides in the fact that apressure loss ofsome three to four inches is inherent in the operationofa conventional cyclone device, which normally conducts the air andentrained particulate matter introduced therein at high velocity throughat least one and usually several complete revolutions about the devicescentral axis. In a system such as previously mentioned wherein l cardsare each supplied air at the rate of 1,000 CFM and at a negativepressure of four inches of water, pressure losses in the duct-work andin the rotating drum and/or other conventional filtering means normallytotal approximately three inches. An additional pressure loss of somethree to four inches entailed by the inclusion ofa conventional cyclonedevice would therefore require that the system realize asuction-pressure of some l0 to l l inches. As will be apparent to thoseskilled in the art, the realization of such a pressure in a systemhandling some l00,000 CFM of air would be exceedingly expensive, interms of the power required and expended.

SUMMARY OF THE INVENTION The present invention provides improved aircleaning apparatus, of the general type described above. which may beemployed in a system servicing I00 carding machines as hereinbeforedescribed, to effectively remove particulate matter from the 100,000 CFMof air handled by such system, and when so employed the total pressureloss in the system may be no more than approximately 7 /2 inches asopposed to the loss of 10 or ll inches incurred when a conventionalcyclone device is present in the system. Additionally, the apparatus ofthe present invention may be fabricated and installed at considerablyless expense than one including a conventional cyclone device, and maybe employed in restricted areas wherein the size of a conventionalcyclone device would not permit its utilization.

In a preferred embodiment of the invention, the apparatus includes acompact unitary housing enclosing a partial-cyclone device, a rotatingdrum filter and other filtering means arranged in sequence forprogressively removing particulate matter from the air conducted throughthe housing during operation of the apparatus. Automatic stripping meansis associated with the rotating drum filter, and the additionalfiltering means disposed downstream of the drum filter preferablyincludes a bank of V-cell filters. The partial-cyclone device is ofgenerally C-shaped configuration, and extends through an arcuatedistance of less than 360 degrees and preferably no more thanapproximately l. Following its introduction into the housing, aircontaining entrained particulate matter is conducted through an inletduct containing adjustable velocity-regulating valve means and isdirected thereby substantially tangentially against the concave innersurface of the aforesaid partial-cyclone device adjacent the upper endportion thereof. Under the impetus of centrifugal force and gravity, amajor portion of the larger-size particulate matter passes along theconcave inner surface of the device to a purge-outlet adjacent its lowerend. The particulate matter and a minor part of the air introduced intothe housing are withdrawn through such outlet and from the housing.Adjacent its axial center portion and intermediate the aforesaid inletand outlet associated therewith, the partial-cyclone device is open soas to permit free passage therefrom of the major portion of the airintroduced therein and partially cleaned thereby. Such air passesdirectly to and through the rotating-drum filter disposed closelyadjacent the partial-cyclone device and downstream therefrom within thehousing. The minor amount of air purged with the particulate matter fromthe housing by the partialcyclone device is, following condensation ofthe particulate matter therefrom exteriorally of the housing. preferablyre-introduced into the housing so as to also pass with the aforesaidmain flow of air first through the rotating-drum filter and thereafterthrough the additional filtering means provided within the housingdownstream from the rotating-drum filter. Due to the precleaning of theair by the partial-cyclone device, the rotating drum-filter and theother filtering means disposed downstream therefrom do not becomeoverloaded during operation, and effectively perform their respectivefiltering functions at all times. In its passage through the housing ofthe apparatus, the air is therefore thoroughly cleaned, yet undergoesonly aminimal pressure loss as compared to that loss in pressure whichwould ensue if the air were first conducted through a conventionalcyclone. Among the factors contributing to such minimal pressure lossare the fact that the present partial-cyclone device conducts theentrained particulate matter only through part of a single revolution,preferably only approximately 180, and is so positioned as to alsopossibly benefit to a slight extent from the force of gravity. Thevelocity of the air introduced into the partial-cyclone device cantherefore be much less than that required for satisfactory operation ofa conventional cyclone, and is so regulated by the adjustable valvemeans associated with the present device as to be just sufficient forremoval of a major part of the larger-size particulate matter entrainedin the air to be cleaned in the particular installation of theapparatus. Further, since the partial-cyclone device is located withinthe same housing as the rotating drum-filter, and is disposed closelyadjacent to and in free communication with the same, duct-type pressurelosses therebetween are virtually non-existent.

DESCRIPTION OF THE DRAWINGS Other features and benefits of the inventionwill be in part apparent and in part pointed out hereinafter in thefollowing description of an illustrative embodiment thereof, whichshould be read in conjunction with the accompanying drawings, in which:

FIG. I is a top plan view, partially diagramatic and partially brokenaway to disclose details of interior construction, of air cleaningapparatus embodying the invention'.

FIG. 2 is an enlarged side elevational view, partially broken away todisclose details of interior construction, of the main housing of theapparatus of FIG. 1;

FIG. 3 is a partially broken away front elevational view of the mainhousing of the apparatus; and

FIG. 4 is an enlarged fragmentary perspective view, partially brokenaway and partially in vertical section taken substantially along line 44of FIG. 1 through the main housing of the apparatus, showing thepartialcyclone device and certain immediately-adjacent componentsdisposed within such housing.

DESCRIPTION OF THE PREFERRED EMBODIMENT finally discharged, aftercleaning thereof, through out-- let duct of assembly 16. Disposed withinhousing 12 for sequentially and progressively cleaning the air passingtherethrough are a partial-cyclone device 22, a rotating-drum filterdevice 24, and additional filtering means 26, all of which are describedin more detail hereinafter. Conduits 28, 30 extending from housing I2respectively interconnect stripping means 32 of drum filter 24 and apurge outlet 34 (FIGS. 2 and 4) of cyclone device 22 with a header 36communicating via a purge fan assembly 38 with a conventionalparticulatematter separating or condenser" device 40 such as thatmanufactured and sold by Saco-Lowell Shops Division of MaremontCorporation. Another conduit 42 returns exhaust air from condenser 40 tohousing 12 downstream from partial-cyclone device 22 and in the vicinityof the drum filter 24 within the housing. With the exception of thevarious inlets-outlets communicating therewith as described above,housing 12 is of airtight exterior construction, but preferably isprovided with suitable access doors 44 (FIG. 3) through which convenientaccess to the interior of the housing may be realized when desired.

Referring now particularly to FIGS. 2 and 4, platelike valve member 18is disposed within and extends across substantially the full width ofthe portion of the inlet duct 14 located inwardly of housing 12. Member18 is pivotally mounted along its upstream edge to the lower part ofduct 14, as by means of a suitable hinge 46, so as to permit adjustmentof its pivotal position to vary as desired the effective cross-sectionalarea of duct 14 and therefore the velocity of the air and entrainedparticulate matter introduced into housing 12 through duct 14. Tofacilitate adjustment of the pivotal position of plate-like member 18, athreaded rod 48 secured to its downstream edge projects therefrom anarcuate slot 50 provided in the adjacent end wall of housing 12. Slot 50has suitable resilient sealing strips 52 associated therewith to preventleakage of air therethrough. An operating knob 54 threadably secured tothe outer end of rod 48 may be rotated in one direction to cause thesame to bear against the adjacent wall of housing 12 and thereby secureplate-like member 18 in a desired position of pivotal adjustment. Byrotating knob 54 in the opposite direction and thereafter moving thesame longitudinally of slot 50, the pivotal position of member 18 may bevaried as desired. Suitable indicia (not shown) may be provided inassociation with slot 50 and knob 54, if desired, to facilitate desiredplacement of plate-like member 18.

Partial-cyclone device 22 comprises a generally C- shaped baffle member56 which extends, through an arc of approximately degrees and about asubstantially horizontal imaginary axis, between the mouth of inlet duct14 adjacent the top of housing 12 and that of purge outlet 34 adjacentthe bottom of housing 12. The aforesaid axis about which arcuate bafflemember 56 extends lies in approximately the same vertical plane and isapproximately equidistant between the mouths of inlet duct 14 and purgeoutlet 34. One side of C- shaped member 56 is closed by the adjacent endwall of housing 12, while the opposite side of member 56 is closed by awall 58 extending the full height of housing 12 but only partiallyacross the width thereof, as is best shown in FIG. 4.

Air and entrained particulate matter introduced into housing 12 throughinlet duct 14 is discharged by such duct substantially tangentiallyagainst the concave inner surface of the upper end portion of bafflemember 56. The velocity of the incoming air and particulate matter areso adjusted by valve plate 18 that centrifugal force assisted perhaps tosome extent by gravity, causes a major portion of the larger sizeparticulate matter (e.g., 95 percent of the fibrous particulate matterhaving a length of 1/64 inches or more) and a minor portion of the airto be directed by curved baffle member 56 along the length thereof andinto purge outlet 34. The same is then withdrawn through conduit 30 bypurge fan assembly 38 and thereafter directed to the particulate-matterseparating device 40 disposed exteriorly of housing 12. Onlyapproximately or less of the air introduced through inlet duct 14 intohousing 12 is withdrawn therefrom through purge outlet 30 and, aspreviously indicated, such air may be and preferably is subsequentlyreturned to housing 12 from particulatematter separating device 40 byreturn conduit 42. The remaining 90 percent or more of the incoming airdirect by inlet duct 14 against the upper end portion of C-shaped bafflemember 56 passes therefrom, in a partially cleaned state and asindicated by the directional arrows in FIG. 4, through the large opencentral area disposed adjacent the imaginary axis of curvature of member56 and between the mouths of duct 14 and purge outlet 34. Such air thenfreely passes generally longitudinally of housing 12, through thesizable open area disposed forwardly of interior wall 58 and below duct14, to that central portion of the housing enclosing rotating-drumfilter 24.

Rotating-drum filter 24 is of a known type having a closed end 60disposed adjacent partial-cyclone device 22, an open end 62, andsuitable filtering media 64 ex tending about and defining its peripheralcylindrical surface. Drum 24 is mounted for rotation about its centralaxis, which preferably is substantially aligned with the axis ofcurvature of baffle member 56 of partialcyclone device 22, by suitableend-supports 66. The open end portion 62 of drum 24 projects through anair-tight sealing partition 63 extending transversly within housing 12,and suitable drive means 70 are associated therewith for impartingrotation to drum 24. Stripping means 32 comprises a suction head 72mounted by a suitable support 74 for reciprocatory movementlongitudinally of drum 24, under the impetus of suitable drive means(not shown), closely adjacent the filter media 64 defining thecylindrical peripheral surface of drum 24. A flexible tube or conduit 76interconnects suction head 72 and the conduit 28 leading from housing 12and to the previously-described header 36 disposed exteriorly of thehousing. As will be apparent to those skilled in the art, thepartiallycleaned air introduced into the vicinity of drum 24, primarilyfrom partial'cyclone device 22 and to a much lesser extent from returnconduit 42 of device 40, passes generally radially inwardly through thedrums filter media 64 and, following such filtration, is dischargedgenerally axially of the drum through its open end 62. Particulatematter filtered from the air by media 64 is periodically stripped fromthe latter by suction head 72, and delivered by purge-fan assembly 38through conduits 76, 28 and header 36 to particulatematter separatingdevice 40.

Further filtration of the now twice-cleaned air discharged from open end62 of drum filter 24 is achieved by the additional filtering means 26disposed downstream of drum filter 24 within housing 12. As is shown inFIGS. 1 and 3, such additional filtering means preferably includes abank of V-cell filters 78, which afford a relatively large surface areafor filtration of the air passing therethrough, and may be followed byan array of planar filters 80. Filters 78, 80 preferably extend, asshown, across substantially the full width and height of housing 12.

The air finally passing from housing 12 and discharged through outletduct 20 of fan assembly 16 will be substantially free of entrainedparticulate matter. and will have undergone only a minimal pressure lossduring its passage through housing 12. Of particular importance in theforegoing regard is the fact that partialcyclone device 22 of theapparatus, while removing a major portion of the entrained particulatematerial within the incoming air and thereby preventing overloading ofthe filtering means disposed downstream therefrom, occasions a pressureloss of only approximately one-half of an inch, as compared to thepressure loss of some three to four inches inherent in the operation ofa conventional cyclone device. Since the effective operating path ofdevice 22 is less than a full revolution, and preferably is onlyapproximately l80 the velocity of the air and particulate matterdirected by duct 14 into device 22 need not be of the higher magnituderequired in a conventional cyclone and is adjusted by plate-like valvemember 18 so as to be considerably less than such magnitude. Theparticular velocity realized by adjustment of valve plate 18 will varydepending upon the amount of particulate material entrained within theair to be cleaned, since lesser velocities will suffice for lesserconcentrations of particulate material, but in any event need not belarge. Additionally, since device 22 is disposed within the same unitaryhousing 12 as the remaining downstream filtering means, duct losses arenot increased and fabrication and installation costs and procedures arereduced and simplified.

It will thus be seen that there has been provided an improved aircleaning apparatus realizing the benefits and possessing the featureshereinbefore noted. Although a specific embodiment of the invention hasbeen shown and described, it is to be understood that this was forpurposes of illustration only, and not for purposes oflimitation, thescope of the invention being in accordance with the following claims.

That which is claimed is:

1. Apparatus for cleaning air in textile mills and the like, comprising:

elongate housing means;

means for passing air from which particulate matter is to be removedthrough said housing means;

a plurality of air-cleaning means disposed within and enclosed by saidhousing means for progressively cleaning the air during its passagethrough said housing means;

said air-cleaning means including partial-cyclone means disposed withinsaid housing means and comprising a generally C-shaped baffle memberextending through an arc distance of no more than approximately about asubstantially horizontal axis;

said means for passing air through said housing means including an inletduct communicating with said housing means and said baffle memberadjacent one end of said baffle member for directing incoming air andparticulate matter substantially tangentally against the concave innersurface of said baffle member;

adjustable velocity-regulating valve means within said housing means forregulating the velocity of air and entrained particulate matterintroduced into such partial-cyclone means through said inlet duct, saidvalve means comprising a plate-like member pivotally mounted within saidinlet duct, and valve operating means connected to said plate-likemember for varying the pivotal position thereof and for thereby varyingthe effective flow-area of said inlet duct;

a purge outlet adjacent the end of said baffle member opposite from saidone end thereof for receiving particulate matter directed thereto alongsaid baffle member by centrifugal force;

rotating-drum filter means disposed within said housing means downstreamfrom said partial-cyclone means for receiving and further cleaningpartiallycleaned air discharged from said partial-cyclone means, saiddrum filter means including a generally cylindrical drum rotatable abouta central axis and having filter media extending about the generallycylindrical peripheral surface thereof for filtering the air passingtherethrough and into said drum, and further having at least one openend for dis-. charging the filtered air in a generally axial directionfrom said drum through said open end thereof;

additional filtering means disposed within said housing means downstreamfrom said drum filter means for receiving the air discharged from saiddrumfilter means and for further filtering the same prior to passage ofthe air from said housing means;

particulate-matter separating means disposed exteriorally of saidhousing means;

stripping means disposed within said housing means for strippingparticulate matter from said media of said rotating-drum filter means;

means including a plurality of conduits for conducting particulatematter from said purge outlet of said partial-cyclone means and fromsaid stripping means associated with said rotating-drum filter means tosaid particulate-matter separating means;

and a return conduit for returning exhaust air from said particulatematter separating means to the interior of said housing means at alocation therein downstream from said partial-cyclone means and adjacentsaid rotating drum-filter means.

2. Apparatus as in claim 1, wherein an area intermediate said ends ofsaid baffle member and adjacent the axial center thereof is open forfree passage from said baffle member of air from which particulatematter has been centrifuged.

3. Apparatus as in claim 1, wherein said inlet duct is disposed adjacentthe top of said housing means, and said purge outlet is disposedadjacent the bottom of housing means, and said ends of said bafflemember lie in approximately the same vertical plane.

4. Apparatus as in claim 1, wherein said inlet duct and said housinghave an arcuate slot extending therethrough, and said valve operatingmeans comprises a rod member connected to said plate-like member andextending therefrom through said slot, and an operating knob connectedto the outer end of said rod-like member exteriorly of said housing.

5. Apparatus as in claim 4, including resilient sealing meansoperatively associated with said slot for minimizing leakage of airtherethrough.

6. Apparatus as in claim 1, wherein said additional filtering meansincludes a bank of V-cell filters mounted within said housing meansdownstream from said rotating-drum filter means for further filteringthe air discharged from said rotating-drum filter means prior to passagethereof from said housing means.

7. Apparatus as in claim 6, wherein said additional filtering meansfurther includes an array of substantially planar filters mounted withinsaid housing downstream from said bank of V-cell filters.

1. Apparatus for cleaning air in textile mills and the like, comprising:elongate housing means; means for passing air from which particulatematter is to be removed through said housing means; a plurality ofair-cleaning means disposed within and enclosed by said housing meansfor progressively cleaning the air during its passage through saidhousing means; said air-cleaning means including partial-cyclone meansdisposed within said housing means and comprising a generally C-shapedbaffle member extending through an arc distance of no more thanapproximately 180* about a substantially horizontal axis; said means forpassing air through said housing means including an inlet ductcommunicating with said housing means and said baffle member adjacentone end of said baffle member for directing incoming air and particulatematter substantially tangentally against the concave inner surface ofsaid baffle member; adjustable velocity-regulating valve means withinsaid housing means for regulating the velocity of air and entrainedparticulate matter introduced into such partial-cyclone means throughsaid inlet duct, said valve means comprising a platelike memberpivotally mounted within said inlet duct, and valve operating meansconnected to said plate-like member for varying the pivotal positionthereof and for thereby varying the effective flow-area of said inletduct; a purge outlet adjacent the end of said baffle member oppositefrom said one end thereof for receiving particulate matter directedthereto along said baffle member by centrifugal force; rotating-drumfilter means disposed within said housing means downstream from saidpartial-cyclone means for receiving and further cleaningpartially-cleaned air discharged from said partial-cyclone means, saiddrum filter means including a generally cylindrical drum rotatable abouta central axis and having filter media extending about the generallycylindrical peripheral surface thereof for filtering the air passingtherethrough and into said drum, and further having at least one openend for discharging the filtered air in a generally axial direction fromsaid drum through said open end thereof; additional filtering meansdisposed within said housing means downstream from said drum filtermeans for receiving the air discharged from said drum-filter means andfor further filtering the same prior to passage of the air from saidhousing means; particulate-matter separating means disposed exteriorallyof said housing means; stripping means disposed within said housingmeans for stripping particulate matter from said media of saidrotating-drum filter means; means including a plurality of conduits forconducting particulate matter from said purge outlet of saidpartialcyclone means and from said stripping meaNs associated with saidrotating-drum filter means to said particulate-matter separating means;and a return conduit for returning exhaust air from said particulatematter separating means to the interior of said housing means at alocation therein downstream from said partial-cyclone means and adjacentsaid rotating drum-filter means.
 2. Apparatus as in claim 1, wherein anarea intermediate said ends of said baffle member and adjacent the axialcenter thereof is open for free passage from said baffle member of airfrom which particulate matter has been centrifuged.
 3. Apparatus as inclaim 1, wherein said inlet duct is disposed adjacent the top of saidhousing means, and said purge outlet is disposed adjacent the bottom ofhousing means, and said ends of said baffle member lie in approximatelythe same vertical plane.
 4. Apparatus as in claim 1, wherein said inletduct and said housing have an arcuate slot extending therethrough, andsaid valve operating means comprises a rod member connected to saidplate-like member and extending therefrom through said slot, and anoperating knob connected to the outer end of said rod-like memberexteriorly of said housing.
 5. Apparatus as in claim 4, includingresilient sealing means operatively associated with said slot forminimizing leakage of air therethrough.
 6. Apparatus as in claim 1,wherein said additional filtering means includes a bank of V-cellfilters mounted within said housing means downstream from saidrotating-drum filter means for further filtering the air discharged fromsaid rotating-drum filter means prior to passage thereof from saidhousing means.
 7. Apparatus as in claim 6, wherein said additionalfiltering means further includes an array of substantially planarfilters mounted within said housing downstream from said bank of V-cellfilters.